【作者】 姚利宏；

【导师】 王喜明；

【作者基本信息】 内蒙古农业大学 ， 木材科学与技术， 2010， 博士

【摘要】 人造板是木材工业的重要组成部分,我国人造板产量位居世界第一,胶合板是人造板的主体。由于我国特殊的资源情况,竹木复合材料是人工林资源与竹材资源相结合利用的产物。目前,竹木复合材料产品类型多、用途广,然而对胶合界面特性缺乏深入的研究。因此,本文以毛竹(Phyllostachys pubescens Mazel ex H.de Lebaie)、杉木(Cunninghamia lanceolata(Lamb.)Hook.)和酚醛树脂为研究材料,研究了毛竹和杉木单板的表面粗糙度、接触角、铺张渗透系数对毛竹、杉木以及毛竹和杉木复合材料胶粘剂渗透性能、胶层厚度、胶合性能、界面应力应变分布、界面破坏位移和时间的影响,并对胶合界面微观形态及化学官能团的变化进行了探讨,建立了宏观胶合性能与微观理化性质之间的关系,具体研究内容和结果如下:1)通过接触角测试仪研究了毛竹、杉木单板不同粗糙度表面的润湿性。研究结果表明:材料表面,砂光处理对酚醛树脂胶粘剂在毛竹和杉木单板表面初始接触角、平衡接触角、铺张渗透系数影响显著,砂光处理可以改善毛竹和杉木表面润湿性。2)通过二维轮廓粗糙度和激光共聚焦三维形貌测量仪对毛竹、杉木不同处理表面粗糙度进行了研究。研究结果表明:不同处理表面轮廓算术平均偏差(Ra)、微观不平度十点高度(Rz)、最大轮廓高度(Ry)各测试指标组内差异显著,横纹粗糙度大于顺纹、毛竹青面大于黄面、杉木单板松面大于紧面;激光共聚焦三维形貌仪与二维轮廓粗糙度测量仪对Ra、Rz、Ry三个指标测量结果具有互换性,同时激光共聚焦三维形貌仪可以直观的得出表面粗糙度的表面形貌,可以直接获得理想的二维粗糙度轮廓线,利用三维粗糙度直观的获得粗糙表面的三维面积。3)利用环境扫描电镜和电镜能谱仪研究了毛竹、杉木以及毛竹/杉木复合胶合界面的微观形态。研究结果表明:杉木单板紧面的管胞和木射线处于开放状态,而杉木单板松面部分管胞处于封闭状态,毛竹青面和黄面表面差异小且表面空隙少;杉木胶合界面胶层厚度较大,毛竹胶合界面胶层厚度较小,且毛竹表面薄壁细胞空腔和杉木单板表面管胞以及木射线中有胶粘剂渗入,借助扫描电镜能谱可以将其定位;毛竹/杉木胶合界面断裂时,杉木单板表面管胞、毛竹表面薄壁细胞被撕裂、竹纤维均有被撕裂或拉断的现象。4)通过荧光显微镜对毛竹、杉木以及毛竹/杉木复合胶合界面胶粘剂渗透性能和胶层厚度进行了研究。研究结果表明:不同组坯方式、不同表面处理胶合界面胶粘剂渗透性能、胶层厚度差异明显;横切面和径切面对比研究发现,胶层厚度在两个切面上测量结果偏差较小,具有互换性;两切面间有效渗透差异显著,径切面测量结果大于横切面。5)研究了不同组坯方式、不同粗糙度表面对毛竹、杉木以及毛竹/杉木复合材料胶合性能的影响。研究结果表明:不同组坯方式、不同表面处理对干湿态胶合强度影响显著;毛竹青面胶合强度值最大,毛竹黄面胶合强度次之;杉木单板紧面胶合强度大于松面,毛竹/杉木复合材料胶合强度值介于两类单体材料之间。6)利用数字散斑相关测试方法对毛竹、杉木以及毛竹/杉木胶合界面在不同加载条件下应变场以及界面破坏时的应变分布、断裂的横向和纵向最大位移以及时间进行了研究。研究结果表明:随着加载力的增加,相同部位的应变逐渐增加,且初始段应变快速增加,当加载力达到一定值时,应变增加趋势变缓;胶合界面最大剪切应变位于胶层的端部,不同组坯方式胶合界面破坏时应变差异较大;不同组坯方式、不同粗糙度表面对胶层破坏位移和时间影响较大;纵向位移曲线比较粗糙,然而横向位移比较平滑。7)通过红外光谱分析法对杉木、毛竹胶合前后化学官能团的变化进行了研究。研究结果表明:杉木、毛竹热压前后化学官能团变化较小,胶合过程中有官能团发生变化。更多还原

【Abstract】 Wood-based-panel is played an important role in the world wood industry. As a long term, China has been occupying the largest production of wood-based-panel country of the world. Accroding to the unique resourse situation of China, bamboo/wood composite materials have taken the advantage in the international mark. The properties of bamboo/wood composite plywood, as a main production of wood-based-panel, were studied in this dissertation.In the experiment, Moso bamboo (Phyllostachys pubescens Mazel ex H.de Lebaie) and Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) were adhesived by phenolic resin.The purpose of this dissertation was to reserch the relationship between the properties of composite units-which were included the surface roughness of Moso bamboo/Chinese fir , the contact angle, permeability coefficient-and the adhesive parameters-such as the bond strength, adhesives permeability, layer thickness, interface stress and strain distribution, the interface damage displacement and time of Moso bamboo. In order to establishing the relation The morphology of the bonding interface was observed by environmental scanning electron microscope(ESEM) and chemical functional groups changes were measured through fourier transform infrared(FTIR). Research methods and results were as follows:1) The surface roughness of Moso bamboo and Chinese fir veneer on different wetting properties was measured by contact angle analyzer instrument. The results shows: there were significant influences on the adhesive parameters (the initial contact angle, equilibrium contact angle, permeability coefficient of the phenolic resin adhesive) by types of the materials and the sanding treatments. Therefore, sanding treatment improves the property of surface-wetting of both Moso bamboo and Chinese fir.2) The surface roughness of sanded Moso bamboo and Chinese fir were scaled by two-dimensional contours of roughness and laser confocal three-dimensional shape measuring instrument. The results shows that: the three kinds of parameters about surface roughness including profile arithmetic average error(Ra), ten point height of irregularities(Rz), and maximum height of profile(Ry), were changed significantly on both Moso bamboo and Chinese fir. Comparing with the parallel to grain, the numerical value of surface roughness on the perpendicular to grain was larger. The outer circle of Moso bamboo surface roughness was greater than inner skin. Besides, the tight side of Chinese fir veneer surface roughness was higher than loose side. Laser confocal instrument was a better method which is able to directly obtain perfect two-dimensional roughness contour lines and the three-dimensional space.3) The bond interface of Moso bamboo, Chinese fir and Moso bamboo/Chinese fir of composite materials were studied by environmental scanning electron microscope and electron microscope. The results show that: wood tracheids radiation were open on the tight surface of fir veneer and some wood tracheids were closed on loose side of Chinese fir veneer. There was no difference between outer circle of Moso bamboo and inner skin. The interface layer thickness of Chinese fir was larger than Moso bamboo. There was adhesive infiltration into the surface of parenchyma cells and ray tracheids using scanning electron microscopy surface energy spectrum was able to be located. There were phenomenon that the fir veneer surface of tracheids, parenchyma cell surface and bamboo fiber had been torn or pulled off in interface fracture.4) Bonding interface and the layer thickness of adhesive permeability were studied by fluorescence microscopy. The results indicate that: it was significantly effected on the interface permeability and layer thickness by different surface treatments. Through the comparison studied of cross section and radial section found, there was little difference of layer thickness on the two facets. However, the effective penetration of significant differences and radial section results were larger than that measured by cross-section.5) Bonding performance of different lay up and different surface roughness of Moso bamboo, Chinese fir, Moso bamboo/Chinese fir of composite materials were studied. The results indicate that: different lay-up and different surface treatment affected on wet and dry bonding strength significantly. The bonding strength of outer circle of Moso bamboo was the largest, following by bonding strength of inner skin of Bamboo.The bonding strength of tight side of Chinese fir veneer was larger than the loose side. And the bonding strength of Moso bamboo/Chinese fir of composite materials was between Moso bamboo and Chinese fir.6) The test methods by digital speckle correlation method on strain of Moso bamboo, Chinese fir, Moso bamboo/Chinese fir of composite materials under different loading conditions, different lay up, as well as horizontal and vertical maximum displacement and time relationships were studies. The results show that: with the increase in load force, the strain gradually increased and the increase in the initial segment strain faster. When the force reaches a certain value, the strain increased trend steady. The maximum shear strain of bonding interface in the layer ends, different lay up have quite different strain and destroyed time. Different lay up and different surface roughness affected the layer destruction of displacement and times significantly.Vertical displacement curves was rough, but lateral displacement smooth relatively.7) The interface of Moso bamboo, Chinese fir of chemical functional groups changes before and after was studied by infrared spectroscopy. The results show that the functional groups of Maso bamboo and Chinese fir which had a subtle change before and after hot pressing. However, some functional groups of adhesive layer had changed.更多还原